Abstract
Consumers have always had a propensity to share their personal experiences of products/services/brands
with others. Marketers have long appreciated the importance of such user-generated content and Ernest
Dichter coined the term ‘word of mouth’ (WOM) advertising in 1966. In online environments, electronic
word of mouth (eWOM) has become important to consumers, marketing academics and marketing
practitioners. In an era where technology is ever-developing, the Internet is increasingly playing a vital role
in our lives. In 2021, the number of Internet users had reached 4.54 billion, accounting for 59% of the
world’s population (wearesocial, 2021). It is undeniable that the Internet has had a very significant influence
on people’s lives, thereby also leading to an evolution in customers’ consumption habits (Liu et al., 2020;
Yoo et al., 2013). Customers are now able to shop, communicate, acquire information and share thoughts
without leaving their home, simply by moving their fingers (Hennig-Thurau et al., 2004; Jacobsen & Munar,
2012; Zhang et al., 2011).
Formally put, eWOM refers to any positive or negative statement made by potential, actual, or former
customers about a product or company via the Internet (Hennig-Thurau et al., 2004; Ryan & Jones, 2009).
According to a definition by Hennig-Thurau et al. (2004), any product/service/brand-related user generated
content (UGC) can be seen as eWOM information. Meanwhile, eWOM also exists in most online media
that support users in generating their own content. Therefore, eWOM is a very broad concept that exists in
consumers’ generation of product/service/brand-related content in multiple online media. It is apparent that
eWOM is a near-universal trend that has profoundly influenced the customer decision-making cycle and
business performance. This chapter conceptualises and defines eWOM, highlighting the theoretical foci.
Subsequently, the motivations of consumers’ eWOM engagement are examined, followed by categories of
eWOM-related theories. The chapter concludes by presenting a contemporary view of the concept.